Method for the transmission of data field of technology

ABSTRACT

A method, system and computer program product for the transmission of data from a transmitter to receiver. The present invention is directed to improving data transmission. To this end, the transmission of data is accelerated, and an inband-signaling of information is carried out on an MAC-layer plane, wherein the information is particularly relevant to the base station (BS).

PRIORITY AND CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Ser. No. 10/595,245, PCTfiled on Aug. 30, 2004, which is a national stage entry under 35 U.S.C.§371 of International Application No. PCT/EP04/51958, filed Mar. 29,2006, which claims priority to German application 103 45 220.6 filedSep. 29, 2003, all of which are incorporated herein in their entirety byreference.

FIELD OF THE INVENTION

The present invention relates generally to transmitting data from atransmitter to a receiver in accordance with the Universal MobileTelecommunications System (UMTS) standard.

BACKGROUND

The UMTS radio interface is subdivided into three protocol layers: thephysical layer as Layer 1, the data link layer including MAC, RLC, BMC,PDCP as Layer 2 and the network layer with RRC as Layer 3. Within theprotocol structure of the UMTS air interface, a radio resource controlRRC in the radio network control entity RNC is responsible for thecontrol and allocation of radio resources for all user equipment locatedin a radio cell. Resource management is currently performed on arelatively slow time basis because the corresponding signaling betweenthe user equipment and the RNC is effected via the RRC messages.

An essential task of the MAC-d entity in the MAC layer in thetransmitter is, in the transmit case, to map the data applied via thededicated logical channels above the MAC layer to the dedicatedtransport channels of the physical layer. In the receiver, the task ofthe Mac-d is to distribute the data received on the dedicated transportchannels to the dedicated logical channels. In the receive case, theMAC-d entity again distributes the data received via the dedicatedtransport channels to the relevant dedicated logical channels. On thetransport channels, the data is transmitted in the form of fixed-lengthpacket units, the so-called transport blocks. With regard to the furtherstandardization and evolution of UMTS within the Third GenerationPartnership Project or 3GPP bodies, improvements for fast and efficientdata transmission via the dedicated transport channel are needed.

SUMMARY

An object of the present invention is to improve a data transmissionmethod according to the UMTS standard so as to speed up datatransmission. According to the invention, a method for inband signaling(at the MAC layer level) of information relevant to the UMTS basestation is disclosed. The present invention implements fast andefficient signaling between the user terminal equipment UE and aparticular UMTS base station at the MAC layer level. In the MAC layerlevel it is, therefore, possible according to the invention todifferentiate between data transport blocks and signaling transportblocks and to handle them differently, thereby enabling user data andRRC signaling data to be exchanged between user terminal equipment andbase station in the normal way. Signaling data additionally relevant tothe base Station is only exchanged between user terminal equipment andbase station. This speeds up data transmission particularly in theuplink direction, i.e., from user terminal equipment to a network or tothe base station as part of a following network.

According to the invention, in an architecture of a correspondingcommunication system, RRC functionalities in the form of at least onecontrol and/or data processing means are, therefore, moved from the RNCto the base station. Structural conformity with the existing a UMTSstandard is also implemented. To this end, in particular, suitablesignaling is created by providing appropriate signaling means in thebase station and user terminal equipment. In addition, special signalingtransport blocks and two different transport block formats are created.Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription, Figures and Tables that follow.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates components of a radio communication system accordingto the UMTS standard.

FIG. 2 illustrates a protocol structure of the UMTS air interface.

FIG. 3 illustrates an architecture of the MAC-d entity on the UE side.

FIG. 4 illustrates an uplink transmission scenario.

FIG. 5 illustrates mapping of data from transport channels to thephysical channels.

FIG. 6 illustrates an extended protocol structure of the UMTS airinterface.

FIGS. 7A and 7B illustrate transport block formats.

FIG. 8 illustrates an MAC SDU format in the signaling—transport blockcase.

FIG. 9 illustrates inband signaling.

FIG. 10 illustrates a signaling procedure in the MAC layer according toExample 1 in the downlink direction.

FIG. 11 illustrates a signaling procedure in the MAC layer according toExample 2 in the uplink direction.

FIG. 12 Table 1 lists parameters for the signaling radio bearers.

FIG. 13 Table 2 lists parameters for the radio bearers.

FIG. 14 Table 3 lists the configurations permitted for transport formatcombinations.

FIG. 15 Table 4 lists the parameters for the radio bearers according toan embodiment of the invention.

FIG. 16 Table 5 lists the configurations permitted for transport formatcombinations according to an embodiment of the invention.

DETAILED DESCRIPTION

In the Figures and further explanations, the same reference numerals andabbreviations are consistently used for identical parts, functionalblocks, layers, and the like. Because of progressive standardization atinternational level, the technical terms and designations arepredominantly borrowed from the Anglo-Saxon language area and should beunderstood by one of ordinary skill in the art.

A solution is proposed according to the invention in which onlybase-station-relevant information can be exchanged at MAC layer levelbetween a base station and a user equipment via special signalingtransport blocks. A base station according to the invention, therefore,likewise possesses resource management functions, e.g., forreconfiguring the physical channels or for switching the transportchannel type. In this regard, new signaling mechanisms between a basestation and a user equipment, enabling the base station to perform radioresource management as quickly and efficiently as possible, will also bedefined and described below. To facilitate orientation, the basicprinciples of the network and protocol architecture according to theUMTS standard will first be explained.

FIG. 1 illustrates an example radio communication system FCS operated inaccordance with the Universal Mobile Telecommunications System or UMTSstandard. In FIG. 1, a radio cell CE1, a base station BS1 and ahigher-order radio network control entity RNC1 are disclosed. The basestation BS1 is controlled via an associated data line L1 by thehigher-order radio network control entity RNC1, which monitors theassignment of radio resources in the radio cell CE1 served by the basestation BS1. The base station BS1 is representative of a plurality ofother base stations BS (not shown in detail in FIG. 1) of the radiocommunication system FCS that possess and cover the corresponding radiocells CE. Between the base station BS1 and a radio communicationequipment (in this case, one of the mobile telephones UE1-UE5 in theradio cell CE1) message and/or data signals are transmitted over atleast one predefined air interface Uu according to a multiple accesstransmission method.

In UMTS frequency division duplex or FDD mode, for example, separatesignal transmission in the uplink and downlink direction is achieved bymeans of corresponding separate assignment of frequencies or frequencyranges, uplink signifying signal transmission from the user equipment tothe relevant base station, and downlink denoting signal transmissionfrom the assigned base station to the user equipment. A plurality ofusers or more precisely mobile telephones UE1-UE5 in the same radio cellCE1 are preferably separated via orthogonal codes, in particular,according to the so-called code division multiple access or CDMA method.In this example, a number of user equipments UE1, UE2, UE3, UE4 and UE5are present in the radio cell CE1 of the base station BS1. The UMTS airinterface Uu is subdivided into three protocol layers. FIG. 2illustrates the protocol structure in terms of the dedicated transportchannel DCH. The lowest layer is the physical layer, Layer 1. The nexthigher layer is the data link layer, Layer 2, comprising MAC, RLC, BMCand PDCP. The highest layer is the network layer with the RRC, Layer 3.This architecture is present both in the user equipment UE and in theUMTS network, also known as UMTS Terrestrial Radio Access Network orUTRAN, including the base stations BS and the radio network controlentities RNC. Each protocol layer provides its services to the nexthigher layer via defined service access points.

To make the architecture easier to understand, these service accesspoints are provided with commonly used and unique names such as logicalchannels, transport channels, radio bearers RB, and signaling radiobearers SRB. The protocol architecture shown in FIG. 2 is not onlysubdivided horizontally into the abovementioned layers and units, butalso vertically into the control plane (C-plane), including the physicallayer, MAC, RLC and RRC, and the user plane (U-plane), including thephysical layer, MAC, RLC, PDCP and BMC. Only control data required forsetting up and maintaining a connection is transmitted via the C-plane,whereas the actual user data is transported via the U-plane. Eachprotocol layer or protocol entity has particular functions. The protocolarchitecture is described in detail in [1]. On the network side, thephysical layer is in the relevant base station and radio network controlentity, whereas the MAC, RLC, PDCP, BMC and RRC are in the radio networkcontrol entity only. On the transmitter side, the task of the physicallayer Phys is to ensure reliable transmission of the data coming fromthe MAC layer via the air interface Uu, the data being mapped to therelevant physical channels Phy. The physical layer Phys provides itsservices to the MAC layer via transport channels which specify how andwith which characteristic the data is to be transported over the airinterface Uu. The essential functions of the physical layer Phys includechannel coding, modulation and CDMA code spreading. Correspondingly, onthe receiver side, the physical layer Phys performs CDMA codede-spreading, demodulation and decoding of the received data and thenforwards it to the MAC layer for further processing.

The MAC layer provides its services to the RLC layer via logicalchannels Log that characterize the data type of the transported data.The task of the MAC layer in the transmitter is to map the data presenton a logical channel Log above the MAC layer to the transport channelsTransp of the physical layer Phys. For this purpose, the physical layerPhys provides the transport channels with different transmission rates.One of the essential functions of the MAC layer in the transmitter is,therefore, to select a suitable transport format TF for each configuredtransport channel Transp depending on the instantaneous transmissionrate, the transmitted power and the data priority of the logicalchannels Log mapped to that transport channel Transp. For example, atransport format TF specifies how many MAC packet units, known as atransport block, are sent to the physical layer Phys via the transportchannel Transp per transmission time interval TTI. In the receiver, theMAC layer distributes the transport blocks received on the transportchannels Transp to the logical channels Log. The MAC layer consists ofthree logical units.

The MAC-d entity handles the user and control data that are mapped tothe dedicated transport channels DCH via the corresponding dedicatedlogical channels DTCH (Dedicated Traffic Channel) and DCCH (DedicatedControl Channel). The MAC-c/sh (MAC-control/shared) entity handles theuser and control data of logical channels that are mapped to the commontransport channels such as RACH in the uplink or FACH in the downlink.The MAC-b (MAC-broadcast) entity handles only the radio-cell- relevantsystem information which is broadcast to all the UEs in the relevantradio cell by mapping the logical broadcast control channel BCCH to thetransport broadcast channel BCH. The RLC layer provides its services, inthe case of RRC, via the signaling radio bearers SRB. In the case ofPDCP and BMC, this takes place via the radio bearers RB. The SRB or RBcharacterize how the RLC layer has to deal with the data packets.

For this purpose, for example, the transmission mode for each configuredSRB or RB is defined by the RRC layer: transparent mode TM,unacknowledged mode UM or acknowledged mode AM, the RLC layer beingmodeled in such a way that there is one independent RLC entity per RB orSRB. In addition, the task of the RLC protocol in the transmitter is todivide or combine the user and signaling data of RBs or SRBs intopackets. In the case of the UM and AM transmission modes, the relevantRLC entity stores the copies of the data packets present at an RB or SRBin an RLC transmit buffer until they can be successfully transportedover the air interface Uu by the layers below RLC. The RLC layertransfers the data packets resulting from the dividing or combining tothe MAC layer for further transportation. The RRC protocol isresponsible for setup and cleardown, the reconfiguration of physicalchannels Phy, transport channels Transp, logical channels Log, signalingradio bearers and radio bearers, as well as negotiation of all theparameters of the Layer 1 and 2 protocols. For this purpose, the RRCentities in the RNC and UE exchange corresponding RRC messages via theSRBs. For RRC layer details, see [2]. The PDCP protocol is onlyresponsible for the transmission of packet-switched (PS) domain data.Its main function is to compress or decompress EP header information.The BMC protocol is used on the network side to transmit so-called cellbroadcast messages over the air interface Uu.

The functional basics of the MAC-d entity will now be described. TheMAC-d entity in the MAC layer handles the user and control data whichare mapped via the corresponding dedicated logical channels DTCH(Dedicated Traffic Channel) and DCCH (Dedicated Control Channel) to thededicated transport channels DCH. The relevant details are described in[3]. By way of example, FIG. 3 shows the architecture of the MAC-dentity on the UE side:

-   -   If configured by RRC, the user and control data are mapped by        block transport channel type switching from DTCH and DCCH to        common transport channels such as RACH, for example, and        forwarded to the MAC-c/sh entity for further processing.    -   C/T MUX is used if multiplexing of a plurality of dedicated        logical channels to the same transport channel is performed. In        this case, in order to ensure unambiguous identification, the        data packets from the relevant logical channels have a 4-bit C/T        field added as the MAC header in which the identity of the        logical channel is entered. This enables the MAC-d entity on the        receiver side to clearly identify the logical channel from which        the received data originates.    -   In the case of RLC transparent mode, TM, the data packets are        encrypted (ciphering) in the transmit case or decrypted        (deciphering) in the receive case.    -   The task of the UL TFC selection block is uplink scheduling,        i.e. selecting a suitable transport format combination TFC for        all the configured DCHs depending on the instantaneous        transmission rate, the transmitted power and the data priority        of the dedicated logical channels which are mapped to the        transport channels.

To facilitate understanding of how the protocols relate to one another,an example will now be explained. For this purpose, a scenario isassumed in which the user equipment UE1 in the radio cell CE1 is usingtwo uplink packet services of 64 kbps each in parallel, e.g., forInternet browsing and streaming of data. The UE1 has been allocateddedicated radio resources by the RRC layer in the RNC1 on the basis ofthe current traffic situation in the radio cell CE1 and the requestedquality of service QoS. In detail, the individual protocol layers orprotocol entities have been configured by the RRC layer in the RNC1 forthe downlink and uplink in such a way that a particular QoS, such as acertain guaranteed or maximum data rate and/or a defined transmissiondelay shall be ensured by the Layer 1 and 2 protocols for the durationof the mobile connection. The configuration specified by the RNC1 isthen signaled to the RRC layer in the user equipment UE1.

FIG. 4 illustrates a typical configuration for the uplink transmissionscenario illustrated. In the U-plane, two RBs are specified, i.e., RBIand RB2, via which the user data of the relevant packet service istransmitted. In the RLC layer, each RB is mapped to an RLC entity andlogical traffic channel DTCH. In the C-plane, four 3.4-kbps SRBs SRB1 toSRB4 specified on the basis of the different types of control messagesare mapped to an RLC entity and logical control channel DCCH in the RLClayer. In the MAC-d entity, two transport channels DCH1 and DCH2 areconfigured. The two logical traffic channels DTCH1 and DTCH2 aremultiplexed onto the transport channel DCH1 in the U-plane and the fourlogical control channels DCCH1 to DCCH4 are multiplexed onto thetransport channel DCH2 in the C- plane. In the physical layer, the twotransport channels are channel-coded and multiplexed onto a codedcomposite transport channel CCTrCH of 10 ms frame length. Based on FDDradio transmission technology, the data is transmitted over the airinterface Uu to UTRAN on the CCTrCH after spreading and modulation viathe dedicated physical data channel DPDCH with SF=16. Specific physicallayer control information is transmitted on the dedicated physicalcontrol Channel DPCCH with spreading factor SF=256 to enable thephysical layer in the base station BS1 to also correctly decode the dataon the DPDCH after decoding the control information on the DPCCH.

FIGS. 12 to 14, Tables 1 to 3 summarize the configured parameters forthe signaling radio bearers, radio bearers and the permitted transportformat combinations. For the processing of the data packets in thetransmit buffers of the relevant RLC-entities, the logical channels areassigned different priorities from 1 to 8. Priority 1 constitutes thehighest and priority 8 constitutes the lowest priority. On the basis ofthese priorities, the data packets are preferred by the logical channelshaving a higher priority. In the event of a stalemate situation, i.e.,both or a plurality of logical channels on the same transport channelhave the same priority, the buffer occupancy BO is taken into account asa further criterion. If, in the case of equal priority of, e.g., twological channels on the same transport channel, the buffer status oflogical channel 1 is higher than that of logical channel 2, the data isfirst processed by channel 1.

For the transport channel DCH1, five transport formats TF0 to TF4 in thetransport format set TFS are configured. For example, the transportformat TF2 specifies that, in each transmission time interval TTI of 20ms, two transport blocks TB of size 340 bits are transmitted via theDCH1 to the physical layer where 16 CRC checksum bits are added to eachtransport block for error detection. The two transport blocks are thenjointly channel-coded by a rate ⅓ turbo coder in order to protect themfrom transmission errors that may be caused by the transmission channel.For the transport channel DCH2, on the other hand, only two transportformats TF0 and TF1 in the transport format set TFS are configured.Thus, the transport format TF1 specifies that, in each transmission timeinterval TTI=40 ms, one transport block of size 148 bits is transmittedvia the DCH2 to the physical layer where 16 CRC checksum bits are addedto the transport block for error detection. The transport block is thenchannel-coded by a rate ⅓ convolutional coder.

The coded data of the two transport channels are then jointlymultiplexed onto a CCTrCH frame depending on their respective TTIs. Onthe basis of TTI=20 ms, the data from DCH1 is transmitted over the airinterface to UTRAN in two consecutive frames, whereas the data fromDCH2, on the basis of TTI=40 ms, is transmitted in four consecutiveframes. The permissible combination of transport formats of the twotransport channels DCH1 and DCH2 on the CCTrCH is specified by thetransport format combination set TFCS. The maximum number of possibletransport format combinations TFC is the product of the number oftransport formats configured for each transport channel. It lies withinthe responsibility and control of UTRAN to correctly specify the size ofthe TFCS, i.e., the number and type of the permitted combinations oftransport formats of different transport channels. In practice, thepermitted number of TFCs in a TFCS is less than the theoreticallypossible maximum. In this embodiment, the permitted size of the TFCS=10is also the actual maximum number, also 5 TFs from DCH1 and 2 TFs fromDCH2. These 10 permitted transport format combinations are listed inFIG. 14 Table 3. The notation of the TFCs is defined with i=0 . . . 4and j=0.1 for TF#i from DCH1, TF#j from DCH2.

FIG. 5 illustrates an example of uplink scheduling in which the MAC-dentity has selected the transport format combination TFC8 for datatransmission as a function of the instantaneous transmission situation,the combination TFC8=(TF3, TF1) specifying that the relevant portions ofthe coded data of three transport blocks TB1, TB2, TB3 from DCH1 (=TF3)and of one transport block (TB1) from DCH2 (=TF1) are transmitted on theCCTrCH. To ensure that the physical layer in the base station. BS1 cancorrectly decode the data on the DPDCH, the transport format combinationTFC8 used on the CCTrCH is signaled on the DPCCH as control information.An essential aspect of the present invention is the definition ofspecial signaling transport blocks STB for inband signaling ofbase-station-relevant information at the MAC layer level. This allowsfast and efficient control of radio resources. Without limitinggenerality, it will now be assumed that the base station BS possessesthe following RRC functions:

-   -   Reconfiguration of physical channels in the uplink and downlink    -   Reconfiguration of the transport formats and transport format        combinations in the uplink and downlink    -   Switching of the transport channel type, i.e. from common        transport channels to dedicated transport channels and vice        versa    -   Setting of the uplink SIR_(target) for fast performance control        of dedicated physical channels        Specifically, a solution according to the invention looks as        follows:

1. Extended UTRAN protocol architecture: Within the UTRAN protocolarchitecture, a new entity with the designation Medium Access ControlEnhanced Uplink, abbreviated to MAC-EU, is defined in the MAClayer. Acorrespondingly extended UTRAN protocol architecture is shown in FIG. 6analogously to the depiction in FIG. 2. On the network side the MAC-EUentity is only in the base station, the MAC-EU performing all thefunctions required for inband signaling of base-station-relevantinformation concerning the signaling transport blocks for radio resourcecontrol. These functions include:

-   -   Generating one or more signaling transport blocks for inband        signaling;    -   Selecting a transport channel for transmitting the signaling        transport blocks;    -   Multiplexing signaling transport blocks within the transport        blocks of a transport channel that are to be transmitted;    -   Demultiplexing signaling transport blocks within the received        transport blocks of a transport channel;    -   Forwarding the information transmitted in the signaling        transport blocks to the RRC entity in the base station or UE for        further processing and    -   Checking for reliable transmission or reception of messages in        signaling transport blocks.

Depending on the RRC functionality of the base station BS, various typesof messages are exchanged between the base station BS and a userequipment UE via an STB. This new transport block typically contains,according to the following non-exhaustive list:

-   -   Physical Channel Reconfiguration Control: message from the base        station to the UE to reconfigure the physical channels in the        uplink and downlink.    -   TF Reconfiguration Control: message from the base station to the        UE to reconfigure the transport format and transport format        combinations in the uplink and downlink.    -   Buffer Status Control: message from the base station to the UE        to transmit the current data volume of a particular transport        channel, i.e. the RLC buffer status of all the RBs or logical        channels which are multiplexed into the transport channel.    -   Buffer Status Report: reply from the UE to the base station in        response to the buffer status control message with signaling of        the data volume of the transport channel.

2. Definition of transport block types: Two new transport block formatsare defined for the dedicated logical channels DTCH and DCCH dependingon the MAC-multiplexing, see FIGS. 7A and 7B. Without limitinggenerality, a DCH transport channel is considered in FIGS. 7A and 7B,i.e., in principle the new formats can also be used for the commontransport channels such as RACH in the uplink and FACH in the downlink:

-   -   Case a): DTCH or DCCH are mapped to a DCH transport channel        without multiplexing. In this case only a 2-bit D/C field is        added as a MAC header.    -   Case b): DTCH or DCCH are mapped to a DCH transport channel with        multiplexing. In this case the MAC header consists of the 2-bit        D/C field and the 4-bit C/T field in which the relevant identity        of the logical channel is transmitted.

-   The field is designated D/C as an abbreviation for Data/Control. The    D/C field indicates the transport block type:    -   With D/C=00 a signaling transport block STB is signaled. The MAC        SDU then constitutes the packet unit via which only        base-station-relevant information for radio resource control is        exchanged between user equipment and base station.    -   Correspondingly, D/C=11 signals a normal transport block by        means of which user or RRCsignaling data is transmitted, as        hitherto. The MAC SDU then constitutes the packet unit which        receives the MAC layer via DTCH or DCCH.

3. Structure of the signaling transport block: FIG. 8 shows the generalstructure of the MAC SDU part of a signaling transport block STB viawhich n messages can be transmitted:

-   -   TN UL: this status field or field transmits an uplink        transmission number and is used for tracking the transmission        status in the uplink. The field is k bits long.    -   TN DL: this field transmits a downlink transmission number and        is used for tracking the transmission status in the downlink.        The field is k bits long.    -   Poll: this field is used to request from the receiver an        acknowledgment of successful transmission of a signaling        transport block within a specified time. The field is 1 bit        long.    -   MT: in this field the message type transmitted in the following        message part is specified. The field is 1 bit coded.    -   MP: in this field the message specified by the MT part is        transmitted. The field has a variable length of m bits depending        on the type of message to be transmitted.    -   Flag: this field is used to indicate whether or not the field        MT, i.e., another message, is transmitted in the following        field. The field is 1 bit long.    -   Pad: this field is used to pad out the unused part in the MAC        SDU with so-called dummy bits.

-   The status fields TN UL, TN DL and Poll are used to check for    reliable transmission of messages in a signaling transport block.    This is implemented by the following mechanism:    -   The MAC-EU entity in the UE has an uplink transmission counter        Z1 with an integer value range of 0 to N−1 coded with k bits.        For each STB transmitted in the uplink direction, the current        value of this uplink counter is transmitted in the field TN UL        and then incremented by one. The value of the last DL-STB        received is additionally transmitted in the field TN DL. When        the maximum count has been reached, Z1 is reset to 0 and        incremented once again.    -   Similarly, the MAC-EU entity in the base station has a downlink        transmission counter Z2 with an integer value range of 0 to N−1,        coded with k bits. For each STB transmitted in the downlink        direction, the current value of this downlink counter is        transmitted in the field TN DL and then incremented by one. The        value of the last UL-STB received is additionally transmitted in        the field TN UL. When the maximum count has been reached, Z2 is        reset to 0 and incremented once again.    -   Using the status field Poll, the relevant MAC-EU entities can if        necessary request acknowledgment of successful reception of the        STB within a specified time from the relevant receiver entities,        i.e., by a set poll bit=1.

-   In the case of error-free transmission conditions, the relevant    MAC-EU entities in the receiver receive a sequential numerical order    of signaling transport blocks, i.e., any transmission errors are    detected by breaks in the sequential numerical order.

To summarize, according to the invention there are defined, within theMAC_protocol layer, special signaling transport blocks via which infuture fast and efficient inband signaling for radio resource controlbetween a base station and a user equipment can be implemented, therebyproviding the following advantages. The invention supports an extendedUTRAN protocol architecture with RRC functionality in the base station,so that radio resources can in future be managed closer to the airinterface. In this way, reconfigurations of radio resources in theuplink and downlink can be carried out much more quickly and efficientlyfor a user equipment as a function of the traffic load in a radio cell.Data transmission in the downlink and particularly in the uplink can besignificantly improved in terms of transmission delay and datathroughput.

In the examples which follow, the extended UTRAN protocol architectureshown in FIG. 6 with the new MAC-EU entity in the MAC layer will beconsidered. Without limiting generality, it will be assumed that thebase station possesses the following RRC functions, as already statedabove:

-   -   Reconfiguration of physical channels in the uplink and downlink    -   Reconfiguration of the transport formats and transport format        combinations in the uplink and downlink    -   Switching of the transport channel type, i.e., from common        transport channels to dedicated transport channels and vice        versa    -   Setting of the uplink SIR_(target) for fast performance control        of dedicated physical channels

-   Data transmission between a UE and UTRAN via a dedicated connection    with the following configuration is considered:    -   For uplink and downlink a transmission scenario according to        FIG. 4 is considered.    -   In the U-plane the user data is transmitted on two RBs, i.e.,        RB#1 and RB#2. The configuration of the two RBs is summarized in        FIG. 15 Table 4.    -   In the C-plane, 4 SRBs (SRB#1 to SRB#4) are configured. Their        parameters are summarized in FIG. 12 Table 1.    -   FIG. 16 Table 5 lists the permitted transport format        combinations, a total of 12 combinations now being defined.    -   A transport block format according to case b) in FIG. 7B is        considered, i.e., the MAC header consists of the fields D/C and        C/T.    -   In respect of the format of a signaling transport block        according to FIG. 8, the following configuration is considered:        fields TN UL, TN DL and MT 3 bits long in each case.

Example 1 of an embodiment: inband signaling in the downlink. Thedownlink transmission counter Z2 is in the initial state with the value0 and MAC-EU in the base station has yet to receive a UL-STB from theUE. Because of the current traffic Situation in the radio cell, the basestation wants to send two radio resource control messages to the UE viaa DL-STB within the existing dedicated data transmission between UE andUTRAN:

-   -   Physical Channel Reconfiguration Control for reconfiguring the        dedicated physical channels in the uplink and downlink, e.g.,        new parameters for SF, channelization code and scrambling code.    -   Buffer Status Control for transmitting the current data volume        of the dedicated UL transport channel DCH1.

-   Based on the downlink scheduling, the MAC-d entity in the RNC has    selected TFC9 for data transmission on the CCTrCH, i.e., the    relevant portions of the coded data of four transport blocks (TB1,    TB2, TB3, TB4) from DCH1 (=TF3) and of one transport block (TB1)    from DCH2 (=TF1) are to be transmitted in the physical layer every    10 ms.

Because of the available transmission capacity on DCH1, the MAC-EU inthe base station BS selects this transport channel for transmitting its182-bit signaling transport block. MAC-EU signals the requirement to theMAC-d entity so that only three normal transport blocks are actuallytransmitted over the DCH1. The MAC-EU now generates an STB with thefollowing configuration:

-   -   D/C=00    -   C/T=dummy bits, as this field has no significance in the case of        an STB    -   TN UL=0    -   TN DL=0    -   Poll=0    -   MT=Physical Channel Reconfiguration Control    -   MP1=content of the Physical Channel Reconfiguration Control        message    -   Flag-1=1, in Order to indicate that another message follows    -   MT=Buffer Status Control    -   MP2=content of the Buffer Status Control message    -   Flag-2=0, in order to indicate that another message follows    -   Pad=dummy bits, if required

This STB is then multiplexed by the MAC-EU within the normal transportblocks of DCH1 to be transmitted, as shown in FIG. 9, and passed on tothe physical layer for further processing. The basic signal flow isshown in FIG. 10, the dash-dotted line clearly indicating the physicalseparation of the MAC layer as a logical entity. In order that thephysical layer in the UE can correctly decode the data on the DPDCH, thetransport format combination TFC9 used on the CCTrCH is signaled on theDPCCH as control information. In the MAC-EU entity in the UE, thereceived transport blocks on the DCH1 are evaluated on the basis of theD/C field in the MAC header, and, if D/C=00, the DL-STB1 isdemultiplexed accordingly, The three other transport blocks TB1, TB2 andTB3 are passed on to MAC-d entity for further processing.

Example 2 of an embodiment: inband signaling in the uplink. The uplinktransmission counter Z1 is in the initial state with the value 0 and theMAC-EU in the UE has received the DL-STB from the base station. On thebasis of the received messages, on the one hand the physical channels inthe uplink and downlink are reconfigured while, on the other,measurement of the data volume on the UL-DCH1 is performed. As aresponse thereto, the Buffer Status Report is now to be sent to the basestation via a UL-STB. Based on the uplink scheduling, the MAC-d entityin the UE has selected TFC9 for data transmission on the CCTrCH, i.e.,the relevant portions of the coded data of four transport blocks (TB1,TB2, TB3, TB4) from DCH1 (=TF3) and of one transport block (TB1) fromDCH2 (=TF1) are to be transmitted in the physical layer every 10 ms.

Because of the available transmission capacity on DCH1, the MAC-EUselects this transport channel for transmitting its 182-bit signalingtransport block, MAC-EU signals the requirement to the MAC-d entity sothat only three normal transport blocks are actually transmitted overthe DCH1. The MAC-EU now generates an STB with the followingconfiguration:

-   -   DIC=00    -   CT=dummy bits, as this field has no significance in the case of        an STB    -   TN UL=0    -   TN DL=0    -   Poll=0    -   MT=Buffer Status Report    -   MP1=content of the Buffer Status Report message    -   Flag-1=0, in order to indicate that no other message follows    -   Pad=dummy bits, if required

This STB is then multiplexed by the MAC-EU within the normal transportblocks of DCH1 to be transmitted, as shown in FIG. 9, and passed on tothe physical layer for further processing. The basic signal flow in theuplink direction is shown in FIG. 11 where, in contrast to the situationin FIG. 10, there is no physical Separation of the MAC layer. In orderthat the physical layer in the base station can correctly decode thedata on the DPDCH, the transport format combination TFC9 used on theCCTrCH is signaled on the DPCCH as control information. In the MAC-EUentity in the base station, the received transport blocks on the DCH1are evaluated on the basis of the D/C field in the MAC header, and, ifD/C=00, the UL-STB1 is demultiplexed accordingly. The three othertransport blocks TB1, TB2 and TB3 are passed on to MAC-d entity in theRNC for further processing.

Within the scope of the description of the present invention, referenceis made particularly to the following literature:

-   3GPP TS 25.301: Radio Interface Protocol Architecture-   3GPP TS 25.331: Radio Resource Control (RRC) protocol specification-   3GPP TS 25.321: Medium Access Control (MAC) protocol specification-   In addition, the following abbreviations are used:-   3GPP Third Generation Partnership Project-   AM Acknowledged Mode-   BCCHBroadcast Control Channel-   BCH Broadcast Channel-   BMC Broadcast Multicast Control-   BO Buffer Occupancy-   BS Base Station-   CCTrCH Coded Composite Transport Channel-   CDMA Code Division Multiple Access-   CE Radio cell-   CRC Cyclic Redundancy Check-   D/C Data/Control-   DCCH Dedicated Control Channel-   DCH Dedicated Channel-   DL Downlink-   DPCCH Dedicated Physical Control Channel-   DPDCH Dedicated Physical Data Channel-   DTCH Dedicated Traffic Channel-   FACH Forward Access Channel-   FCS Radio communication system-   FDD Frequency Division Duplex-   IP Internet Protocol-   kbps Kilobits per second-   Log Logical Channel-   MAC Medium Access Control-   MAC-b MAC broadcast-   MAC-c/sh MAC control/shared-   MAC-d MAC dedicated-   MAC-EU MAC Enhanced Uplink-   MP Message Part-   MT Message Type-   PDCP Packet Data Convergence Protocol-   PS Packet-switched-   Phy Physical Channel-   Phys Physical layer-   QOS Quality of Service-   RACH Random Access Channel-   RB Radio Bearer-   RLC Radio Link Control-   RNC Radio Network Controller, radio network control entity-   RRC Radio Resource Control-   SDU Service Data Unit-   SF Spreading Factor-   SIR Signal to Interference Ratio-   SRB Signaling Radio Bearer-   STB Signaling Transport Block-   TB Transport Block-   TF Transport Format-   TFC Transport Format Combination-   TFCS Transport Format Combination Set-   TFS Transport Format Set-   TM Transparent Mode-   TN Transmission Number-   Transp Transport Channel-   TTI Transmission Time Interval-   UE User Equipment-   UL Uplink-   UM Unacknowledged Mode-   UMTS Universal Mobile Telecommunications System-   UTRAN UMTS Terrestrial Radio Access Network

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present invention andwithout diminishing its intended advantages. It is therefore intendedthat such changes and modifications be covered by the appended claims.

1. A method at a user equipment comprising: generating in the user equipment (UE) and at a MAC layer, a Buffer Status Report relevant to a base station; and transmitting, by using inband signaling, the Buffer Status Report from the UE within at least one signaling transport block transmitted by the UE to the base station, wherein the Buffer Status Report indicates an amount of data for transmission in a buffer of a transport channel from the UE to the base station.
 2. The method of claim 1 wherein the Buffer Status Report is transmitted in accordance with an instruction from the base station.
 3. The method of claim 1 wherein the signaling transport block is multiplexed with data transport blocks and transmitted on the transport channel.
 4. The method of claim 2 wherein the instruction requests the Buffer Status Report on multiple radio bearers or logical channels on the transport channel.
 5. The method of claim 1 wherein the transport channel is a dedicated transport channel.
 6. The method of claim 1 wherein the signaling transport block includes padding of dummy bits.
 7. A user equipment comprising: a transmitter to transmit to a base station, using inband signaling, a signaling transport block; and a control plane to generate at a MAC layer a Buffer Status Report, the control plane adapted to include the Buffer Status Report within the signaling transport block, wherein the Buffer Status Report to indicate an amount of data for transmission in a buffer of a transport channel from the user terminal to the base station.
 8. The user equipment of claim 7 wherein the control plane is adapted to multiplex the signaling transport block with data transport blocks to be transmitted on the transport channel.
 9. The user equipment of claim 7 wherein the control plane is adapted to receive an instruction from the base station, and in accordance with the instruction, to generate the Buffer Status Report.
 10. A method at a base station comprising: receiving a signaling transport block from a user equipment on a transport channel, the signaling transport block including inband, a Buffer Status Report, wherein the Buffer Status Report indicates an amount of data for transmission in a buffer of the transport channel from the user terminal to the base station; and extracting at a MAC layer the Buffer Status Report from the signaling transport block.
 11. The method of claim 10 further including transmitting from the base station an instruction to the user equipment to transmit back to the base station the Buffer Status Report.
 12. The method of claim 1 wherein the signaling transport block is multiplexed with data transport blocks and transmitted on the transport channel.
 13. The method of claim 11 wherein the instruction requests the Buffer Status Report on multiple radio bearers or logical channels on the transport channel.
 14. The method of claim 10 wherein the transport channel is a dedicated transport channel.
 15. The method of claim 10 wherein the signaling transport block includes padding of dummy bits.
 16. A base station comprising: a transceiver to communicate with a user terminal using a transport channel; and a radio network control entity that is adapted to receive a signaling transport block from the user equipment on the transport channel, the signaling transport block including inband, a Buffer Status Report generated at a MAC layer, wherein the Buffer Status Report indicates an amount of data for transmission in a buffer of the transport channel from the user terminal to the base station.
 17. The base station of claim 16 wherein the radio network control entity is adapted to cause the transceiver to transmit an instruction to the user equipment to transmit back to the base station the Buffer Status Report. 